At present, hoses are often called upon to carry materials which need to be heated to be applied at a point of usage. Such heating can be required in a manufacturing process as, for example, in the plastics industry, or in road construction to pump asphalt to a desired location for application. At present, the majority of such hoses will utilize heating blanket technologies whereby the hose is wrapped with a heating element, typically an electric resistance heater of some sort. In addition, such hoses are often constructed using thin polytetrafluoroethylene tubes to allow for good flow of the liquids therethrough.
However, current technologies do suffer drawbacks. For example, the thin polytetrafluoroethylene tubes without inner support often kink. For support, present users add square lock liners which, themselves, do not support more than about 20 pound loads. In addition, heavy outer casings employed on such hoses are excessively heavy, are very stiff and do not insulate well resulting in injury to workers handling same.
U.S. Pat. No. 6,049,658 entitled “Flexible Hose for a Flowable Material Application” which issued on Apr. 11, 2000 to Schave et al. discloses a melter for asphalt including a heated hose 74 coupled to a supply line 72, a heating element and a sensor (FIG. 1).
U.S. Pat. No. 5,974,227 entitled “Hot Melt Mix Applicator with Electrically Heated Hose” which issued on Oct. 26, 1999 to Schave shows an electrically heated hose 22 for hot melt mix applications including a heating element 30 and a temperature sensor 122 (FIGS. 4, 4A).
U.S. Pat. No. 4,553,023 entitled “Thermally Insulated Electrically Heated Hose for Transmitting Hot Liquids” which issued on Nov. 12, 1985 to Jameson et al. provides an electrically heated hose 10 including Aramid thermal insulation 84, a Polytetrafluoroethylene tube 20 with a stainless steel wire braiding 21 and heater wires (23a-23d)(FIGS. 1-3).
U.S. Pat. No. 6,043,466 entitled “Hot Runner Heating Clamp,” which issued on Mar. 28, 2000 to Jenko et al. has a system for clamping a heater to a cylindrical member including a heater coil 120 with coiled portions (122, 14) and a removable thermocouple 128 (FIGS. 7A-7C).
Thus, there is a need for a hose having a heating element which eliminates the shortcomings of the prior art.